Sphero-telecentric Objective for Corneal Imaging
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Solution Overview
Problem
Current optical coherence tomography (OCT) systems, particularly SDOCT, face limitations in imaging the cornea due to signal decay away from the center, oblique scanning angles, and inadequate depth of view, which hinder accurate visualization and diagnosis of dry eye disease and corneal abnormalities.
Innovation Solution
The development of a sphero-telecentric objective with an aspheric optical element and a telecentric scanning input beam zoom system, which includes a movable lens group configuration to control numerical aperture and focus, allowing for improved imaging of curved surfaces like the cornea with constant optical path lengths and reduced refractive warping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If telecentric optics are used for cornea imaging, then imaging depth is sufficient, but signal falls off away from cornea center and field of view is constrained
Solution Approach 1:
The patent applies a curved focal field design where the focal surface is curved to match the corneal curvature. This allows the imaging system to maintain focus and signal strength across a wider field of view while imaging the entire cornea, resolving the trade-off between imaging depth and field of view by adapting the focal geometry to the biological surface being imaged.
2Area of stationary object
If scanning beam impinges cornea at oblique angles away from center, then wider field of view is achieved, but refraction occurs causing image warping
Solution Approach 1:
The scanning system is designed with a curved focal field that matches the corneal surface curvature. This geometric matching ensures that scanning rays impinge the cornea at angles that minimize refraction-induced warping while maintaining a wide field of view, thereby achieving both extensive coverage and high image accuracy.
3Manufacturing precision
If aspheric optical element is added to create sphero-telecentric objective, then constant optical path lengths and reduced warping are achieved, but device complexity increases
Solution Approach 1:
An aspheric optical element is incorporated into the objective to create a sphero-telecentric system. This single aspheric element provides constant optical path lengths across the field of view and reduces image warping, achieving high optical precision while adding minimal complexity compared to multiple spherical elements.
Solution Approach 2:
The patent changes the optical parameters by introducing an aspheric surface with specific curvature characteristics. This parameter change in the optical design enables constant optical path lengths and reduced warping effects, achieving improved image accuracy through a fundamental change in the optical geometry rather than through complex mechanical adjustments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution provides enhanced resolution and a wider field of view for corneal imaging, enabling more accurate diagnosis of dry eye disease and corneal abnormalities by maintaining image quality and depth across the field, thus overcoming the limitations of traditional OCT systems.
Implementation Method 1
an aspheric optical element... sphero-telecentric objective... constant optical path lengths
Implementation Method 2
the scanning optical coherence tomography beam impinges the cornea at an increasingly oblique angle. The beam then refracts into the cornea
Data Source
Figure 1A~1C
Figure 2
Figure 3A~3I
AI summary
Scanning optical beam imaging systems for imaging a surface with convex curvature are provided. The systems include a sphero-telecentric objective, including an aspheric optical element and a path equalizing element (PEQ).